Clinical treatment of a ventilated patient often requires that the breathing characteristics of the patient be monitored to detect the effects of a particular ventilation strategy on a patient or changes in the patient's breathing patterns. Many modern ventilators include a display that provides a visual display of various parameters regarding the patient's breathing patterns and/or the operation of the ventilator, and may allow the caregiver to adjust ventilator settings to select or adjust the ventilation strategy being implemented. For example, a ventilator may display one or more of the following parameters: airway pressure, exhaled volume, ventilation mode, type of breath, mean airway pressure, peak airway pressure, PEEP/CPAP pressure, plateau pressure, respiratory rate, I:E ratio, tidal volume, minute volume, and spontaneous minute volume.
In addition, some ventilators may display various waveforms indicating one or more parameters of the patient's breathing patterns and/or the operation of the ventilator over time, e.g., over a breath cycle. For example, such waveforms may include a flow-volume loop (which graphically depicts the flow of air compared to the total volume inspired or expired), and a pressure-volume loop (which graphically depicts the change in circuit pressure compared to the total volume inspired or expired).